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mass transit

In the middle of the 19th century, the
motive power for urban mass transportation advanced to independent steam locomotives, which could pull many cars and thus serve busier routes. Steam locomotives operated over longer distances than cable cars, and they were more reliable and considerably faster because they did not depend on a single, fragile cable. Beginning in Berlin in 1879, steam was...

railroads

Although
motive power for a train-set can be incorporated into a car that also has passenger, baggage, or freight accommodations, it most often is provided by a separate unit, the locomotive, which includes the machinery to generate (or, in the case of an electric locomotive, to convert) power and transmit it to the driving wheels. Today there are two main sources of power for a locomotive: oil...